Before treatment, children with ASD had higher RV peak diastolic kinetic energy than controls, which normalized after treatment once diastolic ASD streaming was abolished; RV indexed KE fell after treatment, while LV peak systolic KE rose with LV volume and LV peak diastolic KE did not change.
Key Findings
Results
RV peak diastolic kinetic energy was higher in children with ASD than in controls before treatment and normalized after treatment.
22 patients with ASD (8 males, median 8.5 yr [IQR 5-12]) were compared with 11 matched controls using 4-D flow CMR.
Before treatment, RV peak diastolic KE was higher in ASD than in controls (P = 0.02).
After treatment, RV peak diastolic KE was no longer different from controls (P = 0.42).
Normalization coincided with abolishment of diastolic ASD streaming.
Results
Indexed RV peak systolic and diastolic KE (iKE) decreased after ASD treatment, suggesting altered RV energetics beyond volume changes.
Repeat CMR was done in 16/22 patients (72.7%) at a mean ± SD of 7.7 ± 1.7 months after treatment.
iKE was indexed for ventricular volume at the time of peak KE.
RV peak systolic and peak diastolic iKE both decreased after treatment (both P < 0.01).
The authors interpret this as RV energetic changes not solely attributable to RV volume changes.
Results
After treatment, RV iKE in patients with ASD was comparable to that of controls.
Systolic RV iKE: P = 0.18 versus controls.
Diastolic RV iKE: P = 0.87 versus controls.
Results
LV peak systolic KE increased after ASD treatment together with increased LV volumes, whereas LV peak diastolic KE did not change.
Within the ASD group, LV peak systolic KE increased with increased LV volumes after treatment (P < 0.01).
LV peak diastolic KE did not change significantly (P = 0.09).
The authors attribute the systolic increase to improved LV filling conditions.
Discussion
The RV and LV showed different peak diastolic KE responses to treatment, which may reflect different diastolic ventricular remodeling.
RV peak diastolic KE was elevated before treatment and normalized, while LV peak diastolic KE showed no significant change.
The authors state that this difference warrants further investigation.
Elevated RV diastolic KE is thought to reflect both the large ventricular blood volume and the streaming shunt volume from the ASD.
What This Means
This study used a type of heart MRI that tracks blood flow in three dimensions plus time to measure the kinetic energy of blood moving through the heart in children with an atrial septal defect (a hole between the upper heart chambers). The researchers compared 22 children with the defect to 11 children without it, and re-scanned 16 of the patients about 8 months after the hole was treated.
Before treatment, the right ventricle showed higher kinetic energy during filling than in controls. This appeared to reflect both its enlarged blood volume and the extra stream of blood passing through the hole. After treatment, this measure returned to normal. Even after accounting for ventricular size, the right ventricle's kinetic energy decreased after treatment, which suggests its energy handling changed in ways beyond simple size changes. On the left side, kinetic energy during contraction rose after treatment as the left ventricle filled better, while kinetic energy during filling did not change significantly.
This research suggests that kinetic energy measured with 4-D flow MRI could help describe how the heart adapts to abnormal loading and recovers after repair of a congenital defect. The study was small, and the authors note that more work is needed to understand why the right and left ventricles responded differently during filling.
Clausen H, Friberg E, Arvidsson P, Liuba P, Sjöberg P. (2026). Exploring cardiac kinetic energy in children with atrial septal defects: a case-control study.. American journal of physiology. Heart and circulatory physiology. https://doi.org/10.1152/ajpheart.00342.2026